fungi_ecologyfandomcom-20200213-history
Glossary
16s Mitochondrial RNA 16s Mitochondrial RNA is part of a genetic sequence which defines a prokaryotic ribosome. Ribosomes are common to all living things, and they are "highly conserved", that is to say that they change extremely slowly over evolutionary time. After much research, Carl Woese and George E. Fox chose 16s Mitochondrial RNA, because of the sequence's highly conserved nature, to construct a phylogenetic tree of life. Aseptate Coenocitic Aseptate, or Coenocitic, hyphae are much less separated into compartments by septa than are septate hyphae, In aseptate hyphae, the septa compartmentalise fruiting bodies (reproductive regions) and sections which are no longer growing from the apically growing regions. Biotrophic A fungus that forms a long term symbiotic relationship with another organism. It absorbs nutrients from a host organism's living cells. Chitin A flexible but strong polysaccharide, also found in insect exoskeletons. The plasma membranes of hyphae are enclosed and strengthened by the chitin. Eukaryotes Eukaryotes are organisms made up of cells which contain a nucleus and other organelles; these are themselves contained within membranes. They are often, but not always, multicellular. Eukaryotes belong to the domain Eukaryota, one of three domains: Bacteria, Archea and Eukaryota. Heterokaryon This is a cell formed with two nuclei from genetically different individuals. Heterotrophic Heterotrophs feed by absorbing soluble nutrients from outside their bodies. Hyphae A Hyphae is a tubular, rigid walled structure. The hyphae walls are made of chitin and surround a plasma membrane which contains the cytoplasm. Karyogamy This is the last step in the fusion of the two nuclei. Mycelium This is an interwoven mass of filaments called hyphae that thread through the soil or other substrate that the fungus is feeding in. Mycorrhizal Main Article: This is the symbiotic and often mutualistic relationship between the roots of a plant and a fungus. Necrotrophic Feeds and grows by killing the cell or cells of the host organism before feeding upon it. Phylogenetic Tree Main article: A "Tree of Life", showing the relationships between each grouping of extant organisms. The three domain model (Bacteria, Archea, and Prokaryota) currently in use was proposed by Carl Woese in 1990. (NASA, 2013) Prokaryotes Prokaryotes are single-celled organisms that do not have nuclei or other organelles. Both Bacteria and Archea are still referred to as prokaryotes, though (through additional work by Carl Woese and others) they are not as closely related as originally thought. Plasmogamy A stage in the sexual reproduction that involves the fusion of protoplasm from two cells, usually hyphae, but that does not involve the fusion of nuclei. Instead the nuclei from two individuals are brought into close proximity with a cell. Saprotrophic Organisms that feed on other organisms which are already dead or things such as animal waste which are non-living. Septate Septate hyphae are separated into compartments by septa, these have pores which allow protoplasm and even organelles to pass. Ribonucleic Acid RNA RNA is a derivative of DNA, Deoxyribonucleic Acid Woronin Bodies These are found behind septa in older, non growing, hyphal regions and block pores in the septa in areas which have aged. (Deacon, 1997)